Technical Field
Certain embodiments of the invention relate to a cold trap and a control method of a cold trap.
Description of Related Art
A cold trap is a device for evacuating a vacuum vessel, and includes a cold panel and a cryocooler which cools the cold panel. A gas having a high boiling point such as water vapor is condensed on a surface of the cold panel, and is removed from the vacuum vessel. The cold panel is cooled so as to reach a temperature at which a vapor pressure of the discharged gas sufficiently decreases. Other gases are discharged through a main vacuum pump such as a turbo-molecular pump provided in the vacuum vessel.